SIST EN 674:2011

Glass in building - Determination of thermal transmittance (U value) - Guarded hot plate method

This European Standard specifies a measurement method to determine the thermal transmittance of glazing with flat and parallel surfaces. Structured surfaces, e.g. patterned glass, can be considered to be flat.
This European Standard applies to multiple glazing with outer panes which are not transparent to far infrared radiation, which is the case for soda lime silicate glass products, borosilicate glass and glass ceramics. Internal elements may be far infrared transparent.
The procedure specified in this European Standard determines the U value ) (thermal transmittance) in the central area of glazing. The edge effects, due to the thermal bridge through the spacer of an insulating glass unit or through the window frame are not included. Furthermore energy transfer due to solar radiation is not taken into account.
The procedure specified in this European Standard should generally only be considered when the calculation method detailed in EN 673 is inappropriate or unsuitable.
The document for the calculation of the overall U value of windows, doors and shutters (see [3]) gives normative reference to the U value evaluated for the glazing components according to this standard.
A vertical position of the glazing is specified.
U values evaluated according to the present standard are used for product comparison as well as for other purposes, in particular for predicting:
-   heat loss through glazing;
-   conduction heat gains in summer;
-   condensation on glazing surfaces;
-   the effects of the absorbed solar radiation in determining the solar factor (see [1]).
Reference should be made to [4], [5], or other European Standards dealing with heat loss calculations for the application of glazing U values determined by this standard.
The determination of the thermal transmittance is performed for conditions which correspond to the average situation for glazing in practice.

Glas im Bauwesen - Bestimmung des Wärmedurchgangskoeffizienten (U-Wert) - Verfahren mit dem Plattengerät

Diese Europäische Norm beschreibt ein Messverfahren, das zur Bestimmung des Wärmedurchgangs-koeffizienten von hermetisch abgeschlossenen Verglasungen mit ebenen und parallelen Oberflächen dient. Strukturierte Oberflächen, z. B. Ornamentglas, dürfen als eben angesehen werden.
Diese Europäische Norm gilt für Mehrfachverglasungen mit äußeren Scheiben, die für Strahlung im fernen Infrarotbereich undurchlässig sind, was bei Produkten aus Natron-Kalk-Glas, Borosilicatglas und Glaskeramik der Fall ist. Die inneren Elemente dürfen jedoch für Strahlung im fernen Infrarotbereich durchlässig sein.
Das in dieser Europäischen Norm festgelegte Verfahren dient der Bestimmung des U Wertes ) (Wärmedurch-gangskoeffizient) im mittleren Bereich der Verglasung. Die Randwirkungen infolge der Wärmebrücke durch den Abstandshalter einer Isolierglaseinheit oder durch den Fensterrahmen sind nicht berücksichtigt. Die Wärmeübertragung durch Sonneneinstrahlung wurde ebenfalls nicht berücksichtigt.
Das in dieser Europäischen Norm festgelegte Verfahren sollte im Allgemeinen nur dann angewendet werden, wenn das in EN 673 ausführlich beschriebene Berechnungsverfahren ungeeignet ist.
Das Dokument für die Berechnung des Gesamt-U Werts von Fenstern, Türen und Abschlüssen (siehe [3]) enthält eine normative Verweisung auf den nach dieser Norm berechneten U Wert für die Verglasungselemente.
Es ist eine senkrechte Lage der Verglasung vorgeschrieben.
Die nach der vorliegenden Norm bestimmten U Werte werden sowohl für Produktvergleiche als auch zu weiteren Zwecken herangezogen, insbesondere für die Voraussage von:
-   Wärmeverlusten durch Verglasungen;
-   Erhöhungen der Wärmeleitung im Sommer;
-   Tauwasserbildung auf Glasoberflächen;
-   Auswirkungen der absorbierten Sonnenstrahlung auf die Bestimmung des Sonnenfaktors (siehe [1]).

Verre dans la construction - Détermination du coefficient de transmission thermique, U - Méthode de l'anneau de garde

La présente Norme européenne spécifie une méthode de mesure utilisée pour déterminer le coefficient de transmission thermique de vitrages dont les faces sont planes et parallèles. Les faces structurées, par exemple le verre imprimé, peuvent être considérées comme planes.
La présente Norme européenne est applicable aux vitrages multiples dont les faces externes ne sont pas transparentes au rayonnement infrarouge lointain, ce qui est le cas des produits verriers de silicate sodo-calcique, du verre borosilicaté et du vitrocéramique. Les éléments internes peuvent être transparents au rayonnement infrarouge lointain.
Le mode opératoire défini dans la présente Norme européenne détermine l’expression de la valeur « U » ) (transmission thermique) dans la partie centrale du vitrage. Les effets de bord dus au pont thermique de l’intercalaire d’un vitrage isolant ou du châssis de fenêtre ne sont pas considérés. De plus, le transfert d’énergie dû au rayonnement solaire n’est pas pris en considération.
En général, il convient que le mode opératoire défini dans la présente Norme européenne soit pris en considération seulement lorsque la méthode de calcul détaillée dans l’EN 673 est inappropriée ou ne convient pas.
Le document relatif au calcul de la valeur U globale des fenêtres, portes et fermetures (voir [3]) donne une référence normative de la valeur U évaluée pour les composants verriers selon la présente norme.
La position verticale du vitrage est définie.
Les valeurs U évaluées selon la présente norme sont utilisées pour la comparaison de produits, mais peuvent également servir à d’autres buts, en particulier afin de prévoir :
-   la perte de chaleur au travers des vitrages ;
-   les gains de chaleur par conduction en été ;
-   la condensation sur les faces des vitrages ;
-   l’appréciation du rayonnement absorbé dans la détermination du facteur solaire (voir [1]).

Steklo v gradbeništvu - Ugotavljanje toplotne prehodnosti (U-vrednost) - Metoda z vročo ploščo

Ta evropski standard opredeljuje merilno metodo za ugotavljanje toplotne prehodnosti zasteklitve s ploskimi in vzporednimi površinami. Strukturirane površine, npr. vzorčasto steklo, se lahko štejejo za ravne. Ta evropski standard velja za večkratno zasteklitev z zunanjimi šipami, ki pri skrajni infrardeči svetlobi niso prozorne, kot so mešanice natrijevega hidroksida in kalcijevega hidroksida, borosilikatno steklo in steklena keramika. Notranji elementi so lahko prozorni pri skrajni infrardeči svetlobi. S postopkom, ki ga opredeljuje ta evropski standard, se določa vrednost U (toplotna prehodnost) v osrednjem delu zasteklitve. Robni učinki zaradi toplotnega mostu med vmesnikom izolacijske steklene enote ali skozi okvir okna niso zajeti. Tudi prenos energije zaradi sončnega sevanja ni upoštevan. Postopek, opredeljen v tem evropskem standardu, se praviloma upošteva le, če je metoda izračuna, ki je podrobno opisana v EN 673, neprimerna ali neustrezna.

General Information

• Status: Published
• Public Enquiry End Date: 30-Dec-2010
• Publication Date: 10-Oct-2011
• ICS: 81.040.20 - Glass in building
• Technical Committee: STV - Steklo, svetloba in razsvetljava v gradbeništvu
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 29-Jun-2011
• Due Date: 03-Sep-2011
• Completion Date: 11-Oct-2011
• Directive: 89/106/EEC - Construction products
• Mandate: M/135 - Mandate to CEN/CENELEC concerning the execution of standardization work for harmonized standards on flat glass, profiled glass and glass block products
• Ref Project: EN 674:2011 - Glass in building - Determination of thermal transmittance (U value) - Guarded hot plate method

Relations

• Replaces: SIST EN 674:1999 - Glass in building - Determination of thermal transmittance (U value) - Guarded hot plate method
• Effective Date: 01-Sep-2011
• Replaces: SIST EN 674:1999 - Glass in building - Determination of thermal transmittance (U value) - Guarded hot plate method
• Effective Date: 08-Jun-2022

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN 674:2011
01-november-2011
1DGRPHãþD
SIST EN 674:1999
6WHNORYJUDGEHQLãWYX8JRWDYOMDQMHWRSORWQHSUHKRGQRVWL8YUHGQRVW0HWRGD]
YURþRSORãþR
Glass in building - Determination of thermal transmittance (U value) - Guarded hot plate
method
Glas im Bauwesen - Bestimmung des Wärmedurchgangskoeffizienten (U-Wert) -
Verfahren mit dem Plattengerät
Verre dans la construction - Détermination du coefficient de transmission thermique, U -
Méthode de l'anneau de garde
Ta slovenski standard je istoveten z: EN 674:2011
ICS:
81.040.20 Steklo v gradbeništvu Glass in building
SIST EN 674:2011 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 674:2011

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SIST EN 674:2011


EUROPEAN STANDARD
EN 674

NORME EUROPÉENNE

EUROPÄISCHE NORM
June 2011
ICS 81.040.20 Supersedes EN 674:1997
English Version
Glass in building - Determination of thermal transmittance (U
value) - Guarded hot plate method
Verre dans la construction - Détermination du coefficient de Glas im Bauwesen - Bestimmung des
transmission thermique, U - Méthode de l'anneau de garde Wärmedurchgangskoeffizienten (U-Wert) - Verfahren mit
dem Plattengerät
This European Standard was approved by CEN on 29 April 2011.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same
status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland,
Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.





EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2011 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 674:2011: E
worldwide for CEN national Members.

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SIST EN 674:2011
EN 674:2011 (E)
Contents Page
Foreword .3
1 Scope .4
2 Normative references .4
3 Terms and definitions .5
4 Basic formula .5
5 Brief outline of the measuring procedure .5
6 Test apparatus .5
7 Dimensions of the specimens .6
8 Preparation of the specimens .6
9 Performance of the measurements.7
10 Evaluation of the results .7
10.1 Thermal resistance of the multiple glazing .7
10.2 Declared U Value.7
10.3 Design U value .8
11 Expression of the results .8
11.1 U values .8
11.2 Thermal resistance .8
11.3 Intermediate values .8
12 Test report .9
12.1 Information included in the test report .9
12.2 Identification of each glazing specimen .9
12.3 Cross section of the specimen .9
12.4 Results .9
Bibliography . 11

2

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SIST EN 674:2011
EN 674:2011 (E)
Foreword
This document (EN 674:2011) has been prepared by Technical Committee CEN/TC 129 “Glass in building”,
the secretariat of which is held by NBN.
This European Standard shall be given the status of a national standard, either by publication of an identical
text or by endorsement, at the latest by December 2011, and conflicting national standards shall be withdrawn
at the latest by December 2011.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 674:1997.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.
3

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SIST EN 674:2011
EN 674:2011 (E)
1 Scope
This European Standard specifies a measurement method to determine the thermal transmittance of glazing
with flat and parallel surfaces. Structured surfaces, e.g. patterned glass, can be considered to be flat.
This European Standard applies to multiple glazing with outer panes which are not transparent to far infrared
radiation, which is the case for soda lime silicate glass products, borosilicate glass and glass ceramics.
Internal elements may be far infrared transparent.
1)
(thermal transmittance) in the
The procedure specified in this European Standard determines the U value
central area of glazing. The edge effects, due to the thermal bridge through the spacer of an insulating glass
unit or through the window frame are not included. Furthermore energy transfer due to solar radiation is not
taken into account.
The procedure specified in this European Standard should generally only be considered when the calculation
method detailed in EN 673 is inappropriate or unsuitable.
The document for the calculation of the overall U value of windows, doors and shutters (see [3]) gives
normative reference to the U value evaluated for the glazing components according to this standard.
A vertical position of the glazing is specified.
U values evaluated according to the present standard are used for product comparison as well as for other
purposes, in particular for predicting:
 heat loss through glazing;
 conduction heat gains in summer;
 condensation on glazing surfaces;
 the effects of the absorbed solar radiation in determining the solar factor (see [1]).
Reference should be made to [4], [5], or other European Standards dealing with heat loss calculations for the
application of glazing U values determined by this standard.
The determination of the thermal transmittance is performed for conditions which correspond to the average
situation for glazing in practice.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
EN 12898, Glass in building  Determination of the emissivity
ISO 8302:1991, Thermal insulation  Determination of steady-state thermal resistance and related properties
 Guarded hot plate apparatus

1) In some countries the symbol k has been used hitherto.
4

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SIST EN 674:2011
EN 674:2011 (E)
3 Terms and definitions
For the purposes of this standard, the following terms and definitions apply:
3.1
U value
parameter of glazing: which characterizes the heat transfer through the central part of the glazing, i.e. without
edge effects, which states the steady-state density of heat transfer rate per temperature difference between
2
the environmental temperatures on each side, and which is given in watts per square metre Kelvin [W/(m ·K)]
3.2
declared value
U value obtained under standardized boundary conditions
NOTE See 10.2.
4 Basic formula
The U value depends on the thermal resistance of the multiple glazing and on the external and internal
surface heat transfer coefficients according to the relation:
1 1 1
= R+ +
U h h
e i
(1)
where
2
[ ]
(m ⋅K)/W
R is the thermal resistance of the multiple glazing in square metres Kelvins per Watt ;
2
[(m ⋅K)/W]
h is the external surface heat transfer coefficient in Watts per square metre Kelvin ;
e
2
[(m ⋅K)/W]
h is the internal surface heat transfer coefficient in Watts per square metre
...

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.SORãþRGlas im Bauwesen - Bestimmung des Wärmedurchgangskoeffizienten (U-Wert) - Verfahren mit dem PlattengerätVerre dans la construction - Détermination du coefficient de transmission thermique, U - Méthode de l'anneau de gardeGlass in building - Determination of thermal transmittance (U value) - Guarded hot plate method81.040.20Steklo v gradbeništvuGlass in buildingICS:Ta slovenski standard je istoveten z:FprEN 674kSIST FprEN 674:2010en,fr,de01-december-2010kSIST FprEN 674:2010SLOVENSKI
STANDARD



kSIST FprEN 674:2010



EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
FINAL DRAFT
FprEN 674
October 2010 ICS 81.040.20 Will supersede EN 674:1997English Version
Glass in building - Determination of thermal transmittance (U value) - Guarded hot plate method
Verre dans la construction - Détermination du coefficient de transmission thermique, U - Méthode de l'anneau de garde Glas im Bauwesen - Bestimmung des Wärmedurchgangskoeffizienten (U-Wert) - Verfahren mit dem Plattengerät This draft European Standard is submitted to CEN members for unique acceptance procedure. It has been drawn up by the Technical Committee CEN/TC 129.
If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are aware and to provide supporting documentation.
Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without notice and shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre:
Avenue Marnix 17,
B-1000 Brussels © 2010 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. FprEN 674:2010: EkSIST FprEN 674:2010



FprEN 674:2010 (E) 2 Contents Page Foreword .31Scope .42Normative references .43Terms and definitions .54Basic formula .55Brief outline of the measuring procedure .56Test apparatus .67Dimensions of the specimens .68Preparation of the specimens .79Performance of the measurements.710Evaluation of the results .710.1Thermal resistance of the multiple glazing .710.2U Value .711Expression of the results .811.1U values .811.2Thermal resistance .811.3Intermediate values .812Test report .812.1Information included in the test report .812.2Identification of each glazing specimen .812.3Cross section of the specimen .912.4Results .9Bibliography . 11 kSIST FprEN 674:2010



FprEN 674:2010 (E) 3 Foreword This document (FprEN 674:2010) has been prepared by Technical Committee CEN/TC 129 “Glass in building”, the secretariat of which is held by NBN. This document is currently submitted to the Unique Acceptance Procedure. This document will supersede EN 674:1997. CEN/TC 129/WG9 "Light and energy transmission, thermal insulation" prepared a working draft based on the document ISO/DIS 10291, Glass in building  Measuring method for the determination of the thermal transmittance of multiple glazing (U value)  Guarded hot plate method, a document that was prepared by ISO/TC 160, "Glass in building". This was published in 1997 as EN 674. This edition is a revision of EN 674:1997. The main change in this edition is that the internal and external heat transfer coefficients have been amended slightly to reflect changes to EN 673. Clarification is also given in the scope that the procedure specified in this European Standard should generally only be considered when the calculation method detailed in EN 673 is inappropriate or unsuitable. kSIST FprEN 674:2010



FprEN 674:2010 (E) 4 1 Scope This European Standard specifies a measurement method to determine the thermal transmittance of glazing with flat and parallel surfaces. Structured surfaces, e.g. patterned glass, can be considered to be flat. This European Standard applies to multiple glazing with outer panes which are not transparent to far infrared radiation, which is the case for soda lime silicate glass products, borosilicate glass and glass ceramics. Internal elements may be far infrared transparent. The procedure specified in this European Standard determines the U value1) (thermal transmittance) in the central area of glazing. The edge effects, due to the thermal bridge through the spacer of an insulating glass unit or through the window frame are not included. Furthermore energy transfer due to solar radiation is not taken into account. The procedure specified in this European Standard should generally only be considered when the calculation method detailed in EN 673 is inappropriate or unsuitable. The document for the calculation of the overall U value of windows, doors and shutters (see [3]) gives normative reference to the U value evaluated for the glazing components according to this standard. A vertical position of the glazing is specified. U values evaluated according to the present standard are used for product comparison as well as for other purposes, in particular for predicting:  heat loss through glazing;  conduction heat gains in summer;  condensation on glazing surfaces;  the effects of the absorbed solar radiation in determining the solar factor (see [1]). Reference should be made to [4], [5], or other European Standards dealing with heat loss calculations for the application of glazing U values determined by this standard. The determination of the thermal transmittance is performed for conditions which correspond to the average situation for glazing in practice. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 12898, Glass in building  Determination of the emissivity ISO 8302:1991, Thermal insulation  Determination of steady-state thermal resistance and related properties  Guarded hot plate apparatus
1) In some countries the symbol k has been used hitherto. kSIST FprEN 674:2010



FprEN 674:2010 (E) 5 3 Terms and definitions For the purposes of this standard, the following terms and definitions apply: 3.1 U value parameter of glazing: which characterizes the heat transfer through the central part of the glazing, i.e. without edge effects, which states the steady-state density of heat transfer rate per temperature difference between the environmental temperatures on each side, and which is given in watts per square metre Kelvin [W/(m2·K)] 3.2 declared value U value obtained under standardized boundary conditions NOTE See 10.2. 4 Basic formula The U value depends on the thermal resistance of the multiple glazing and on the external and internal surface heat transfer coefficients according to the relation: 1U=R+1he+1hi (1) where R is the thermal resistance of the multiple glazing in square metres
...